I checked posts by a well known paper patcher named idahoron on another website and he doesn't lube the paper when sizing the paper patched bullet.
But the bullet does have paper on it when he sizes it.
He also mentioned in another thread that he [generally] uses paper that has cotton in it, and that he expects the paper to fall off after it's fired or it can affect accuracy.
He stated:
" I don’t use any lube on the paper when I am sizing the paper patched bullet. The reason is the lube can and does cause the paper to rip off the bullet when seating the bullet. I size dry and add some lube when I am target shooting but leave them dry when I am hunting. " --->>>
https://www.huntingnet.com/forum/bla...-part-2-a.html
He's shoots muzzle loaders and it would seem that he doesn't want to contaminate the powder charge with lube.